Self-contained disposable syringe

ABSTRACT

A self-contained disposable syringe including a syringe barrel with an open rear end and a needle mounted on the forward end. The needle has a passage therethrough which communicates with the interior of the barrel. A plunger is positioned within the syringe barrel and is movable with respect to the barrel. A needle shield is normally positioned in sealing engagement with the forward end of the syringe barrel and surrounds the needle so as to protect the needle from damage and loss of sterility. A removable seal on the rear end of the syringe barrel normally provides a compact sealed self-contained disposable syringe in sterile condition and suitable for shipment and storage. The needle shield is adapted for removal from the forward end of the barrel and is adapted for engagement with the rear end of the plunger to form finger gripping means on said plunger to facilitate the movement of the plunger with respect to the barrel when the sealed syringe is open for use.

United States Patent Welch [54] SELF-CONTAINED DISPOSABLE SYRINGE [72]Inventor: Joseph T. Welch, Skyline Lakes, NJ.

[73] Assignee: Becton Dickinson and Company, East Rutherford, NJ.

[22] Filed: April 6, 1970 [21] Appl. No.: 26,021

[52] U.S.Cl. ..l28/2l8 S, 128/221 [51] Int. Cl. ..A6lm 05/00 [58]FieldofSem-ch ..128/2l5,2l8 P,l28D,218S, 128/221 [56] References CitedUNITED STATES PATENTS 2,700,386 [[1955 Ogle ..l28/215 2,728,341 12/1955Roehr .128/218 D 3,485,239 l2/l969 Vanderbeck .....l28/2l8 5 2,592,3814/1952 Blackman ..128/218 P 2,953,243 9/1960 Roehr ....l28/2l5 X 877,9462/1908 Overton .....128/218 P 3,072,120 l/1963 Sharp et a1... ..128/2l53,016,896 l/1962 Van Sickle... 128/215 P UX 3,270,743 9/1966 Gingras128/215 978,488 12/1910 Roesch ..l28/218 D [451 July 18, 1972 3,381,8135/1968 Coanda et a1. ..128/22l X FOREIGN PATENTS OR APPLICATIONS 448,3893/1968 Switzerland 128/221 Primary Examiner-Joseph S. ReichAttorney-Kane, Dalsimer, Kane, Sullivan & Kurucz ABSTRACT Aself-contained disposable syringe including a syringe barrel with anopen rear end and a needle mounted on the forward end. The needle has apassage therethrough which communicates with the interior of the barrel.A plunger is positioned within the syringe barrel and is movable withrespect to the barrel. A needle shield is normally positioned in sealingengagement with the forward end of the syringe barrel and surrounds theneedle so as to protect the needle from damage and loss of sterility. Aremovable seal on the rear end of the syringe barrel normally provides acompact sealed self-contained disposable syringe in sterile conditionand suitable for shipment and storage. The needle shield is adapted forremoval from the forward end of the barrel and is adapted for engagementwith the rear end of the plunger to form finger gripping means on saidplunger to facilitate the movement of the plunger with respect to thebarrel when the sealed syringe is open for use.

10 Claims, 2 Drawing Figures m RM y 3 mr W I Fm nY M 1 ATTORNEYSPatented July 18, 1972 BACKGROUND OF THE INVENTION In normal commercialproduction, disposable syringes are generally contained in a packagingmedium which entails the use of one or more elements to contain andprotect the syringe from damage during shipment and handling.Additionally, the packages employed are designed to retain the syringein a sterile condition during the shipping, handling and storage thereofuntil it is desired to use the-syringe.

Packages of this type tend to be bulky and consequently consume morestorage space per unit than is desirable. Furthermore, when the packageis opened and the syringe removed there are often portions of thepackage which have to be removed by fracture or some other means andthen discarded.

Naturally with a packaging medium employed to contain each individualsyringe or a multiplicity of syringes, the cost of providing thepackaging contributes significantly to the overall cost of eachindividual disposable syringe. It is desirable that a disposable syringebe manufactured at as low a cost as possible thereby facilitating thesale of a disposable syringe at a low price. Furthermore, as previouslydiscussed, the use of a packaging medium to contain the syringe addsadditional and unnecessary bulk to each individual syringe which cansignificantly detract from valuable storage space in a hospital or otherstorage area.

From the above comments, it is readily apparent from the state of theart that it would be extremely advantageous to provide a syringe whichconsists of the usual components of plunger, needle, needle shield andbarrel and also constitutes its own package which will maintain asterile interior prior to use as well as protect the frangible portionsof the syringe such as the needle from damage. Furthermore, it wouldalso be ad vantageous to provide such a syringe which may be easilydisassembled from its packaging arrangement and assembled into itsoperating arrangement with a minimum amount of effort and time. Thiswould be advantageous in providing a syringe which is equivalent to thepreassembled syringe in package form now on the market where no assemblysteps are necessary. Therefore, the syringe which forms its own packageshould be readily and easily adaptable from its packaged configurationto its assembled configuration in as few steps and as quickly aspossible.

SUMMARY OF THE INVENTION With the above considerations in mind, amongthe primary objectives of this invention is to provide a syringeincluding a plunger, needle, needle shield and barrel which in normalassembly forms its own package and will maintain a sterile interiorprior to use. No additional packaging components are required with theexception of a paper or plastic cover sealed to the end of the barreland possibly the shield if desired. The self-contained syringe willmaintain the interior portions thereof in a sterile condition duringshipping, handling and storage and additionally will protect thefrangible portions of the assembly such as the needle. Furthermore, aminimum number of components are involved since no parts are used as apackage which allows the syringe and package combination of thisinvention to be manufactured at a cost approximately equal to that ofthe usable disposable syringe without the additional cost of the packagemeans. Naturally, this provides a syringe having a minimum bulk sincethere are no excess parts and therefore the required storage space perunit is considerably decreased. Still further, an object of thisinvention is to provide a selfcontained disposable syringe wherein inthe preparation of the syringe for use, the time required for thispreparation is minimized since no components need be removed ordisassembled and discarded. The shield is adapted to be removed from theneedle and assembled to the plunger rod in one motion therebytransforming the package syringe into a syringe ready for immediate usequickly and efiiciently.

In summary, a self-contained disposable syringe is provided whichincludes a syringe barrel having an open rear end and a needle mountedon the forward end thereof. Theneedle has a passage therethroughcommunicating with the interior of the barrel. A plunger is normallypositioned within the barrel and is movable with respect to the syringebarrel. A needle shield is normally in sealing engagement with theforward end of the syringe barrel and in surrounding relationship withthe needle so as to protect the needle from damage and loss ofsterility. Removable sealing means is positioned on the rear end of thesyringe barrel thereby normally providing a compact sealed,self-contained disposable syringe in sterile condition and suitable forshipment and storage. The needle shield is adapted for removal from theforward end of the barrel and adapted for engagement with the rear endof the plunger to form finger gripping means on the plunger tofacilitate the movement of the plunger with respect to the barrel whenthe sealed syringe is opened for use.

With the above objects, among others, in mind reference is had to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a central sectional view of the selfcontaine'd disposablesyringe of this invention shown in its normally sealed sterile packagedcondition; and

FIG. 2 is a central sectional view thereof showing the syringe with itscomponents in their unpackaged condition and with the syringe assembledfor immediate use.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 of the drawing shows theself-contained disposable syringe 20 of the invention in its sterilepackaged form. The syringe assembly in package form basically consistsof a syringe barrel 21, a needle 22, a plunger 23 and a needle shield24. In the embodiment shown, both open ends of the package are sealedwith separate sealing means. Sealing means 25 covers the end of needleshield 24 distal from syringe barrel 21 and sealing means 26 covers therear end of syringe barrel 21.

Syringe barrel 21 is a conventional type of syringe barrel which isconstructed of a plastic material which lends itself readily todisposability. The syringe barrel is hollow and of a general cylindricalconfiguration and has a reduced forward cylindrical end portion 27.Reduced portion 27 has a bore 28 therethrough which communicates at itsforward end with the exterior of the syringe barrel and at the rear endwith the interior of syringe barrel 21. It may also be noted that theportion of syringe barrel 21 immediately adjacent the forward reducedportion is tapered into a conical configuration to facilitate flow offluid into and out of the syringe barrel and also proper engagement withthe stopper mounted on the forward portion of plunger 23 as will bediscussed in greater detail below.

The forward tip of the bore 28 is flared outwardly to facilitatereception of the needle 22 when it is combined with syringe barrel 21 inthe formation of the syringe assembly. Needle or cannula 22 is a commoncommercial type of syringe needle metallic in nature and having a bore29 therethrough. The forward end of cannula or needle 22 has a pointedpuncture tip 30 for insertion into a fluid source. The rear end 31 ofcannula 22 generally has a blunt configuration and communicates with theinterior of the main body portion of barrel 21. Cannula 22 may beretained in position within reduced forward end 27 by any common bondingmeans such as an epoxy resin. Reduced forward end 27 has a number ofspaced longitudinal ribs 34 on its outer surface to provide additionalrigidity and strength to end 27.

Extending from the main portion of barrel 21 is an annular skirt 32which has the same outer diameter as the main portion of barrel 21 and alarger inner diameter than forward reduced portion 27 of syringe barrel21. It is not necessary that skirt 32 have the same outer diameter asthe main portion of barrel 21. Annular skirt 32 as shown extends atleast as far forward as the forward tip of reduced portion 27 and issubstantially concentric with reduced portion 27 and needle 22. Skirt 32does not necessarily have to extend as far forward as the tip of portion27. The recess 33 formed between the outer surface of reduced portion 27and skirt 32 forms a reception space for a portion of needle shield 24as will be discussed in greater detail below.

The rear end portion 35 of syringe barrel 21 has a larger inner andouter diameter than the main body portion of barrel 21 and is connectedthereto by means of a tapered integral conical shaped portion 36 whichis of the same diameter at its rear end as rear portion 35 and has thesame diameter at its forward end as the main body portion of barrel 21.The purpose of this larger diameter portion 35 on the syringe barrel 21is for readily facilitating the engagement of needle shield 24 withplunger 23 as will be discussed in greater detail below. A pair ofdiametrically opposed finger gripping flanges 37 extend outwardly fromsyringe barrel 21 intermediate the larger diameter upper portion 35 andthe main portion of syringe barrel 21. These flanges facilitate thegripping of the syringe when it is in actual use.

Plunger 23 may assume a variety of different configurations with theprincipal criteria being that it be a rigid member preferably of a lowcost material such as plastic and be of a length which permits-it to belocated entirely within syringe barrel 21 when the selfcontaineddisposable syringe is in the sealed packaged condition. A plurality ofspaced longitudinal ribs 38 extend almost the entire length of plunger23 with the exception of its forward end portion. These ribs 38 serve torigidify plunger 23 and also form an engaging surface for shield 24 whenit is connected to plunger 23 to form the finger gripping portion ofplunger 23 when the syringe is opened and prepared for use. A retaininglug 55 is on the plunger adjacent the rear end thereof to assist inmaintaining shield 24in position on the rear end of plunger 23 duringuse. Lug 55 engages with the inner surface of the forward portion of theshield in a tight frictional engagement to provide increased retentionforce to hold the shield in position on the plunger.

The forward end portion of plunger 23 is in the form of a small diametercylindrical projection 38 terminating in a flanged tip 39. The point ofengagement between projection 38 and flanged tip 39 forms a shoulder 40to facilitate engagement and retention of a flexible stopper 41 mountedon the forward end of plunger 23. Stopper 41 may be constructed of anycommon type of elastomeric material commonly used in the art today suchas a flexible rubber or plastic material. Furthermore, alternatively,the stopper may be formed integrally with the plunger as one member.Stopper 41 has a recess 42 interiorly thereof to receive flanged tip 39as shown in the drawings. In this manner, stopper 41 is mounted toplunger 23 and is moved longitudinally within barrel21 as plunger 23 ismoved longitudinally within barrel 21. A pair of annular projections 43on stopper 4] frictionally engage with the inner surface of syringebarrel 21 to form a sealing surface therebetween so that when plunger 23is withdrawn in a normal manner, fluid may be drawn into the cavity 44formed between the forward tip of stopper 41 and the rear end 31 ofcannula 22. It can be readily seen that the steps of operating thesyringe are similar to those employed in the operation of syringes ofthis type.

Turning to needle shield 24, which also may be constructed of a commontype of plastic material, it will be noted that the main body portion 45is cylindrical in configuration and has substantially the same inner andouter diameter as a portion of syringe barrel 21. This provides for asubstantial uniform diameter intermediate the end portions of thesyringe assembly 20 when in its sealed condition. In this sealedcondition, needle shield 24 has one end proximal the syringe barrel 21and one end distal the syringe barrel 21. The distal end 46 has a flangeon the circumference of its outer edge to receive.

sealing means by an adhesive bond or other common fastening means. Theproximal end 47 has a reduced outer diameter substantially less than theouter diameter of the main body portion 45 of needle shield 24. Thisreduced end portion 47 of needle shield 24 is substantially cylindricalin configuration. The outer surface of reduced end portion 47 has a pairof annular rings 48 in parallel relationship to one another andprojecting therefrom. The resultant outer diameter on reduced portion 47provided by annular rings 48 and the engagement between the innerdiameter of skirt 32 form a tight frictional engagement when reduced endportion 47 is inserted into recess 33 provided between skirt 32 andreduced forward portion 27 of syringe barrel 21. The engagement occurswith sufficient friction so that when the deformation of rings 48occurs, reduced proximal end 47 will snap into position within theforward end of syringe barrel 21 thereby forming a seal .therebetweenthereby preventing contamination of needle 22.

As shown in FIG. 1, the ends may be sealed by means 25 and 26 at eachend of disposable syringe 20 respectively. The type of material utilizedfor sealing means 25 and 26 may vary according to the type ofsterilization process used. If the disposable syringe 20 is to be gassterilized, the material utilized for sealing means 25 and 26 would bein the form of a porous paper which is gas permeable and which willmaintain sterility after the gas sterilization process. Naturally thegas sterilization process utilized is one commonly known in the art. Ifother methods of sterilization are to be employed such as by radiation,sealing means 25 and 26 may take the form of an impermeable paper,plastic, paper-foil, laminate or other similar material in which casethe syringe would be hermetically sealed and sterilized. Naturally, ifthis method is to be employed, sealing means 25 may be eliminated andthe main portion of shield 24 including its distal end 46 may be formedof an integral plastic material. The shown design configuration would bechanged to facilitate manufacture of shield 24. The reason this may beaccomplished will be discussed below when it will be readily seen thatthere is no necessity that the distal end 46 of needle shield 24 beopened for operation of the syringe. However, for purposes of theembodiment shown in FIGS. 1 and 2 sealing means 25 and 26 are in theform ofa gas permeable paper and disposable syringe 20 as shown in FIG.1 has been gas sterilized and appears in its sealed condition.

It also should be noted that there may or may not be engagement betweenthe forward lip 48 of syringe barrel 21 and shoulder 49 fall at thejuncture between reduced proximal end 47 and main body portion 45 ofneedle shield 44. Engagement between rim 48' and shoulder 49 indicatesthat needle shield 24 is completely seated within recess 33 of syringebarrel 21. However, as can be seen from FIG. 1, the sealing engagementsubstantially occurs between the outer rings 48 on proximal end 47 andthe inner surface of skirt 32. It should also be noted that an opening50 is provided to permit communication with the hollow cylindricalproximal end 47 and the main body portion 45 of needle shield 24. Asdepicted, this facilitates reception of needle 22 within needle shield24 through opening 50. It should also be kept in mind that in additionto the use of a gas permeable paper for sealing means 25 and 26 when gassterilization is employed, a gas permeable plastic material such asnylon may also be utilized. When sealing means 25 and 26 takes the formas shown in FIG. I, it may be bonded to the respective ends of syringeassembly 20 by any common means. Furthermore, it is not necessary evenfor gas sterilization that sealing means 25 be at the distal end 46 ofneedle shield 24. When the disposable syringe 20 is shown in its sealedand packaged condition as in FIG. 1, a heat mark 51 may be located atthe juncture of rim 48 and shoulder 49 so as to be utilized as atamper-proof indicator thereby providing a readily usable means ofdetermining if the sterility of the interior of disposable syringe 20may have been affected by previous removal of shield 24.

No additional components are required to provide a completely packaged,self-contained disposable syringe 20 as shown in FIG. 1. Needle shield24 performs the usual function of protecting the needle from damage andin addition it protects the sterility of the needle, and as will bediscussed in greater detail below provides for an extension to plungerrod 23 permitting it to be used in a normal manner when the syringe isopened and used. It should be kept in mind that the plunger prior to useis preferably enclosed completely within syringe barrel 21 thus allowingsealing means 26 to be positioned over the rear end of syringe barrel 21to assist in providing sterility protection and if so desired, ahermetic seal.

FIG. 2 illustrates the self-contained disposable syringe in unpackagedcondition and ready for immediate use. All that need be done toaccomplish this positioning is to withdraw needle shield 24 from theforward end of syringe barrel 21 by supplying suflicient force toovercome the frictional engagement between proximal end 47 and theforward end of syringe barrel 21. Needle shield 24 may then be invertedand projected onto the rear end portion of plunger 23. This exposesneedle 22 for projection into whatever medium is desired.

The unpackaging of syringe may be accomplished in a one-step operation,that is by merely removing needle shield 24 from its sealing position atthe forward end of syringe barrel 21 and by removing sealing means 26and engaging proximal end 47 of needle shield 24 with the rear end ofplunger 23. The syringe is then ready for operation with finger grippingmeans being provided on the main body portion 45 of needle shield 24 andflanges 37 on syringe barrel 21. In fact, in order to assist thegripping surface provided by body portion 45 of needle shield 24 thereare a plurality of spaced longitudinal ribs 52 on the outercircumference of body portion 45 of needle shield 25.

If desired, sealing means 26 may first be removed before shield 24 ispositioned on plunger 23 rather than just merely punctured. Tofacilitate this step, a tab 53 as shown in FIG. 1 may be provided tofacilitate the removal of sealing means 26 from the rear surface of thesyringe barrel 21 to which it is fastened by common means such as anadhesive.

The engagement between the proximal end 47 of needle shield 24 and therear end of plunger 23 is by means of a frictional engagement betweenthe inner surface of proximal reduced end 47 and the outer surface ofribs 38 on plunger 23. The frictional engagement may be of a tightnature due to the deformability of the plastic members so that a snap-onresult may once again be achieved thereby providing a positiveengagement so that when needle shield 24 is moved longitudinally plunger23 will simultaneously be moved longitudinally and there will be littleor no danger of disengagement therebetween. As previously discussed, tofacilitate reception of part of body portion 45 of needle shield 24within syringe barrel 21 the rear portion 35 of syringe barrel 21 is ofan expanded inner and outer diameter. This also facilitates the rapidand easy engagement between needle shield 24 and plunger 23 as well asthe reception of body portion 45 of needle shield 24 within the forwardend portion of syringe barrel 21. Since it is not necessary to provide asealing engagement within syringe barrel 21 where needle shield 24engages with plunger 23, this engagement may take a variety of forms inaddition to the one described above as long as the engagement can beeasily made and will facilitate the movement of plunger 23 as needleshield 24 is moved. There are many types of frictional or snap-onengagements .well known in the art as well as threaded connections whichmay be employed to achieve substantially the same result. All that needbe kept in mind is that a rapid and easy engagement be achieved tofacilitate rapid and efficient transfer of the self-contained disposablesyringe 20 from a sealed packaged condition to an opened ready to usecondition.

As shown in FIG. 2, syringe 20 is in a ready to use position whereby thepuncture end of needle 22 may then be inserted into a fluid source andconnected needle shield 24 and plunger 23 may be withdrawn therebywithdrawing connected stopper 41 and drawing fluid into recess 44 ofsyringe 21 through needle 22 until the desired amount has beencollected. Needle 22 may then be withdrawn from the source of the fluidand combined needle shield 24 and plunger 23 may be projected forwardthereby projecting stopper 41 forward and ejecting the fluid throughneedle 22 into its ultimate reception area. The tapered forward end ofthe main body portion of syringe barrel 2] facilitates the flow of fluidin both directions through needle 22 as stopper 41 is moved along theinterior of syringe barrel 21. As shown, the forward end portion ofstopper 41 may assume a configuration which approximates theconfiguration of the tapered forward portion of barrel 21 to assist inprojecting the greatest possible amount of fluid from within syringebarrel 21. As previously discussed, the sealing engagement betweenannular projections 43 on stopper 41 and the inner surface of barrel 21prevents passage of fluid or air between the forward and rear ends ofstopper 41.

Since the syringe is disposable, once it has been used it may be thendiscarded. All of the components are of a low cost economical materialso that disposability may be readily attained due to the low cost of thesyringe.

The resultant self-contained disposable syringe has a number ofsignificant features which are obvious advantages over the known art.Among these are the fact that a minimum number of components areinvolved since no parts are used as a package with the exception ofsealing means where necessa ry such as sealing means 25 and 26 as shownin FIG. 1. This allows the syringe package combination to bemanufactured for a cost approximately equal to that of the usualdisposable syringe without its package thereby saving the extra costinvolved in providing a packaging means for the disposable syringe. Thisalso facilitates the provision of a syringe having a minimum amount ofbulk since there are no excess parts and thereby permits the storage ofa greater number of units per given storage area.

Furthermore, the preparation prior to use of this syringe is minimizedsince no components need be removed and discarded. The shield can beremoved from the needle and assembled to the plunger rod in one motion.

Thus, the above discussed objectives and advantages of this inventionare most effectively attained.

I claim:

1. A self-contained disposable syringe comprising:

a hollow syringe barrel having a substantially cylindrical main bodyportion and a rear end portion having an open rear end and a largerdiameter than that of said main body portion, and needle mounting meansat the forward end of the barrel;

the needle having a passage therethrough communicating with the interiorof the barrel; plunger including a stopper portion and a rod portionmovable with respect to said syringe barrel and normally positionedwithin said barrel the rod portion being mounted to the rear portion ofsaid stopper portion and extending rearwardly therefrom through saidbarrel main body portion and terminating adjacent said rear end portionwhen said stopper portion is positioned in the forward end of the barrelmain body portion; needle shield having sealing means thereon tonormally position said shield in sealing engagement with the forward endof said syringe barrel and in surrounding noncontacting relationshipwith respect to said needle so as to protect the needle from damage andloss of sterility; removable and piercable sealing means on the rear endof the syringebarrel thereby normally providing a compact sealedself-contained disposable syringe in sterile condition and suitable forshipment and storage; and

said needle shield adapted for removal from the forward end of saidbarrel and adapted for engagement with the rear end of the plunger andhaving an external diameter to permit one end of said shield to beplaced within the rear end portion of the barrel to provide an axialextension of and to form exterior finger gripping means on said plungerto facilitate the movement of said plunger with respect to said barrelwhen the sealed syringe is opened for use to permit operation of thesyringe without the use of any additional parts.

2. The invention in accordance with claim 1 wherein the syringe barrelhas a reduced forward end portion having a bore therethroughcommunicating with the interior of said barrel, said needle beingmounted in the bore of said reduced portion of said syringe barrel andextending forwardly therefrom, an annular skirt extending from saidsyringe barrel in concentric surrounding relationship with said forwardreduced portion of the barrel, said shield-having a substantially hollowcylindrical configuration and having a reduced one end portion, at leastone annular projection on the reduced end of said shield, the reducedend of said shield having an inner diameter and an outer diameter whichpermits the reduced end portion of the shield to be inserted between theinterior of the skirt and the exterior of the reduced forward end of thesyringe barrel with tight frictional engagement between the annularprojections on the reduced end of the shield and the inner surface ofthe skirt of the syringe barrel thereby providing a sealing engagementbetween the shield and the syringe barrel, a shoulder formed where thereduced end portion of the shield meets the remainder of the shield,said shoulder engaging with the forward rim of said skirt when saidreduced end of said shield is engaged with said syringe barrel therebyfacilitating the seating engagement between said shield and said syringebarrel.

3. The invention in accordance with claim 2 wherein said plunger has aresilient member mounted on the forward end thereof with a portion ofsaid resilient member engaging in sealing frictionalengagement with theinner wall of said syringe barrel and slidable with respect thereto tofacilitate the drawing of liquid into said barrel upon retraction ofsaid plunger andprojection of said fluid from said barrel uponprotraction of said plunger.

4. The invention. in accordance with claim 2 wherein said plunger iscylindrical in configuration and has a plurality of spaced longitudinalribs extending from the outer surface thereof along its entire lengthwith the outer diameter of said ribs being less than the inner diameterof the syringe barrel located rearward of the reduced forward portionthereof, the reduced forward end of said shield having an inner diametersubstantially the same as the outer diameter of the longtitudinal ribson the plunger 50 that when said needle shield is removed fromengagement with the forward end portion of said syringe barrel and saidsealing means is removed from the rear end of said syringe barrel, thereduced end portion of said needle shield may be frictionally engagedwith the rear end of said plunger to thereby form said finger grippinghandle for said plunger to facilitate operation of said syringe.

5. The invention in accordance with claim 2 wherein the major portion ofsaid needle shield other than said reduced end portion has a series oflongitudinal projections thereon to facilitate the gripping and handlingof said needle shield when it is being removed from frictionalengagement with the forward end of the said syringe barrel, when it isbeing brought into tight frictional engagement with the rear end of theplunger and when it is being utilized as a finger gripping means toslidably move said plunger with respect to said syringe barre].

6. The invention in accordance with claim 2 wherein the rear end portionof said syringe barrel has a pair of diametrically opposed flangesadjacent the forward end of said larger diameter rear end portion ofsaid syringe barrel to facilitate gripping of said syringe during use.

7. The invention in accordance with claim 1 wherein said plunger,syringe barrel and needle shield are composed of a plastic material.

8. The invention in accordance with claim 1 wherein said sealing meanson the rear end of said barrel is of a gas permeable paper materialadhesively engaged with the rear edge of the syringe barrel tofacilitate gas sterilization of said syringe in its normal sealedcondition.

9. The invention in accordance with claim 8 wherein the end of saidshield distal from said reduced end portion is sealed by means of a gaspermeable paper covering bonded thereto to thereby facilitate the gassterilization of said syringe in the normally sealed condition.

10. The invention in accordance with claim 1 wherein said sealing meansis composed of an impermeable material thereby facilitating theprovision of a hermetically sealed syringe adapted for sterilization byradiation.

1. A self-contained disposable syringe comprising: a hollow syringebarrel having a substantially cylindrical main body portion and a rearend portion having an open rear end and a larger diameter than that ofsaid main body portion, and needle mounting means at the forward end ofthe barrel; the needle having a passage therethrough communicating withthe interior of the barrel; a plunger including a stopper portion and arod portion movable with respect to said syringe barrel and normallypositioned within said barrel the rod portion being mounted to the rearportion of said stopper portion and extending rearwardly therefromthrough said barrel main body portion and terminating adjacent said rearend portion when said stopper portion is positioned in the forward endof the barrel main body portion; a needle shield having sealing meansthereon to normally position said shield in sealing engagement with theforward end of said syringe barrel and in surrounding non-contactingrelationship with respect to said needle so as to protect the needlefrom damage and loss of sterility; removable and piercable sealing meanson the rear end of the syringe barrel thereby normally providing acompact sealed self-contained disposable syringe in sterile conditionand suitable for shipment and storage; and said needle shield adaptedfor removal from the forward end of said barrel and adapted forengagement with the rear end of the plunger and having an externaldiameter to permit one end of said shield to be placed within the rearend portion of the barrel to provide an axial extension of and to formexterior finger gripping means on said plunger to facilitate themovement of said plunger with respect to said barrel when the sealedsyringe is opened for use to permit operation of the syringe without theuse of any additional parts.
 2. The invention in accordance with claim 1wherein the syringe barrel has a reduced forward end portion having abore therethrough communicating with the interior of said barrel, saidneedle being mounted in the bore of said reduced portion of said syringebarrel and extending forwardly therefrom, an annular skirt extendingfrom said syringe barrel in concentric surrounding relationship withsaid forward reduced portion of the barrel, said shield having asubstantially hollow cylindrical configuration and having a reduced oneend portion, at least one annular projection on the reduced end of saidshield, the reduced end of said shield having an inner diameter and anouter diameter which permits the reduced end portion of the shield to beinserted between the interior of the skirt and the exterior of thereduced forward end of the syringe barrel with tight frictionalengagement between the annular projections on the reduced end of theshield and the inner surface of the skirt of the syringe barrel therebyproviding a sealing engagement between the shield and the syringebarrel, a shoulder formed where the reduced end portion of The shieldmeets the remainder of the shield, said shoulder engaging with theforward rim of said skirt when said reduced end of said shield isengaged with said syringe barrel thereby facilitating the seatingengagement between said shield and said syringe barrel.
 3. The inventionin accordance with claim 2 wherein said plunger has a resilient membermounted on the forward end thereof with a portion of said resilientmember engaging in sealing frictional engagement with the inner wall ofsaid syringe barrel and slidable with respect thereto to facilitate thedrawing of liquid into said barrel upon retraction of said plunger andprojection of said fluid from said barrel upon protraction of saidplunger.
 4. The invention in accordance with claim 2 wherein saidplunger is cylindrical in configuration and has a plurality of spacedlongitudinal ribs extending from the outer surface thereof along itsentire length with the outer diameter of said ribs being less than theinner diameter of the syringe barrel located rearward of the reducedforward portion thereof, the reduced forward end of said shield havingan inner diameter substantially the same as the outer diameter of thelongtitudinal ribs on the plunger so that when said needle shield isremoved from engagement with the forward end portion of said syringebarrel and said sealing means is removed from the rear end of saidsyringe barrel, the reduced end portion of said needle shield may befrictionally engaged with the rear end of said plunger to thereby formsaid finger gripping handle for said plunger to facilitate operation ofsaid syringe.
 5. The invention in accordance with claim 2 wherein themajor portion of said needle shield other than said reduced end portionhas a series of longitudinal projections thereon to facilitate thegripping and handling of said needle shield when it is being removedfrom frictional engagement with the forward end of the said syringebarrel, when it is being brought into tight frictional engagement withthe rear end of the plunger and when it is being utilized as a fingergripping means to slidably move said plunger with respect to saidsyringe barrel.
 6. The invention in accordance with claim 2 wherein therear end portion of said syringe barrel has a pair of diametricallyopposed flanges adjacent the forward end of said larger diameter rearend portion of said syringe barrel to facilitate gripping of saidsyringe during use.
 7. The invention in accordance with claim 1 whereinsaid plunger, syringe barrel and needle shield are composed of a plasticmaterial.
 8. The invention in accordance with claim 1 wherein saidsealing means on the rear end of said barrel is of a gas permeable papermaterial adhesively engaged with the rear edge of the syringe barrel tofacilitate gas sterilization of said syringe in its normal sealedcondition.
 9. The invention in accordance with claim 8 wherein the endof said shield distal from said reduced end portion is sealed by meansof a gas permeable paper covering bonded thereto to thereby facilitatethe gas sterilization of said syringe in the normally sealed condition.10. The invention in accordance with claim 1 wherein said sealing meansis composed of an impermeable material thereby facilitating theprovision of a hermetically sealed syringe adapted for sterilization byradiation.